Ineffectual vocal work almost stops popular musical returning (11)
I believe the answer is:
inoperative
'ineffectual' is the definition.
(thesaurus)
'work almost stops popular musical returning' is the wordplay.
'work almost' becomes 'oper' (I can't justify this - if you can you should believe this answer much more).
'stops' means one lot of letters goes inside another.
'popular' becomes 'in'.
'musical' becomes 'evita' (I've seen this before).
'returning' shows that the letters should be reversed in order.
'evita' back-to-front is 'ative'.
'in'+'ative'='inative'
'oper' going within 'inative' is 'INOPERATIVE'.
'vocal' is the link.
I am not very happy about this link. It may belong to another bit of the clue.
Can you help me to learn more?
(Other definitions for inoperative that I've seen before include "It's useless" , "Anna -, Russian poet (Requiem)" , "with no effect" , "Not in working order" .)